a) Field of The Invention
This invention relates to novel topical analgesic compositions containing high concentrations of ibuprofen substantially in solid crystalline form. More particularly this invention relates to novel analgesic compositions for topical administration which are non-irritating, have superior ibuprofen skin penetration with concomitant superior analgesic effect and are cosmetically elegant. The analgesic compositions are preferably creams or lotions and comprise an oil-in-water emulsion having a pH at which the ibuprofen is maintained in substantially solid form suspended in the emulsion.
b) Description of Related Art
There is described in U.S. Pat. No. 4,385,049 a topical preparation system, for example, for pharmaceutical products such as non-steroidal antiinflammatory agents, which are water-in-oil emulsions containing particular emulsifiers. No examples of non-steroidal antiinflammatory drugs are given. An oil-in-water type emulsion is described in U.S. Pat. No. 4,794,106 which is a cream containing hydrocortisone butyrate propionate as the active ingredient and having a pH preferably of 4.5 to 5.5 to increase the storage stability of the hydrocortisone butyrate propionate.